Device for indicating excessive speed of turbine in turbine-driven vehicle



July 17, 1956 SAIVES 2,755,351

DEVICE FOR INDICATING EXCESSIVE SPEED OF TURBINE IN TURBINE-DRIVENVEHICLE Filed May 27, 1952 United States Patent DEVICE FORINDICATINGEXCESSIVE SPEED OF TURBINE IN TURBINE-DRIVEN VEHICLE LeonSaives,,Billancourt, France, assignor to Regie Nationale des UsinesRenault, Billancourt, France, a French corporation Application May 27,1952, SerialNo. 290,367

Claims priority, applieationFrance June 20, 1951 3 Claims. Cl. 200-61.9)

In road-or rail turbine-driven vehicles with a hydraulic or mechanicaltransmission the speed of the turbine increases proportionally to thatof the vehicle or is a direct function thereof.

Particularly when the vehicle concerned is .a locomotive, it may happenthat its speed, on a steep decline, reaches a value higher than thatwhich corresponds to the normal running of the turbine and exposes thelatter to the ranger of bursting.

The present invention has for its object to obviate this danger, byattaching to the turbine .an indicator device which, operating when thespeed becomes too high, warns the engineer, who will then take the stepsnecessary to avoid the danger. This indicating system may, moreover, becombined with other arrangements for automatically placing thetransmission of the vehicle in the neutral position and/or causing theoperation of the brakes.

The indicator system according to the invention causes essentially aswitch which closes an electric circuit controlling the warning signalproper. This switch is itself actuated directly or indirectly by amovable rod. The latter is connected to the turbine, by suitable means,and set in motion :as soon as the critical speed is reached.

Certain embodiments of the invention are shown, by way of non-limitativeexamples, in the accompanying drawings, in which:

Figure 1 shows an embodiment in which the signal is actuated by a devicedepending at the same time on the speed of the turbine and on theposition of the control lever at the driving position;

Figure 2 shows a modification of a detail;

Figure 3 shows a modification in which the sound or other signalcontinues to operate even when the speed of the turbine has been reducedto a value lower than that for which the signal has been set inoperation, and

Figure 4 relates to an embodiment operated electrically.

In :all the figures, the operation of a suitable signal is effected bythe closing of a switch by sliding movement of a rod 3.

Referring to Figure 1, there is shown a cylinder 6, the piston of which,acted on by a spring 7, is subjected to the action of air or liquidpressure depending on the speed of the turbine (this constituting anarrangement which is well known in the turbine art). This pistonoperates on a lever 8 pivoted at 9 and the end 10 of which acts on theend 11 of a balance member 12, the centre 13 of which controls, by a rod3, the switch '4 which ractuates a sound or other signal 5. The end '14of the balance member 12 is con-trolled by a rod 15 of a piston 16subjected to air or liquid pressure depend-ing upon the position of thecontrol lever 1211. the driving position.

The members 15 and 16 may also be replaced by a rod 17, the position ofwhich depends on that of the control lever at the driving position(Figure 2).

The switch 4 will be closed when the points 11 and ice 14-of the balancemember 12 occupy the posit-ions 11' and 14', in other words, when thespeed of the turbine will be too high, the control of this speed being,on the contrary, at its throttled position 14. This will be produced inthe event of racing of the vehicle on a down grade, for example. Thesignal will be prevented from functioning if the speed of the turbinedrops to an acceptable value.

It is naturally possible to use a centrifugal speed-responsive devicevinstead of a pressure-type speed-responsive device such as indicated at6 and 7 in Fig. 1.

Figure 3 shows a rod 18, the enlarged end 19 of which is actuatedthrough a slide 20 by a rod 3 corresponding to .the rod- 3- of-Figure 1. The slide 20-permits a pull to be applied to the rod 18, butnot a push.

When the signal 21 is to be actuated, the rod 3 pulls the rod 18downwardly, the effect of which is to pull a rod 22 towards the right bymeans of a bell-crank lever 23. The rod 22 has a shoulder 24 urgedtowards the left by a spring 25. The movement of the rod 22 towards theright frees a rod 26 of a switch 27. A spring 28 tends to move the rod26 downwardly. When the rod 26 is freed by the rod 22, the switch isclosed and even if subsequently the rod 3 should move upwardly again,the assembly 182322 remains in position, since the end of rod 22 bearsagainst the rod 26. It will only be possible to stop 'the sound signalby pulling the rod 26 upwardly by means of a "button 29, which will freethe rod 22.

Figure 4 shows an electrical arrangement giving the same result as thearrangement according to Figure 3.

The sound signal 21 is set in operation by .a relay 30, the coil ofwhich is energised by a switch 31 set in operation by the rod 3, whichserves the same purpose as the rods 3 of Figures 1 and 3. When the relay30 is excited, switch blades 32 and 33 are attracted and bear againstcontacts 34 and 35, and the current then passes through the switch 32,34 to the signal 21 and also through the switch 33, 35 to a terminal 36of the relay 30, holding the latter energised even if, as a result oflowering of the speed of the turbine, the switch 32, 34 is opened. It isthen only possible to stop the signal 21 by pressing on a button 37 of aswitch '38, which interrupts the current simultaneously at the switches32, 34 and 33, 35. The relay 30 then returns to its position of rest.

Without departing from the scope of the invention, it is possible tovisualise other mechanical or electrical solutions for causing thedisplacement of the rod 3.

The signalling device which been described may be combined with a systemfor placing the transmission in neutral, particularly with that systemwhich form the subject of the application of the present applicant,Serial No. 290,368, filed simultaneously with this application for meansfor automatically limiting the speed of turbines driving vehicles byplacing the transmission in the neutral position, and means forautomatically limiting the speed of turbines driving vehicles byapplying the brakes.

I claim:

1. A device for indicating excessive speed of the turbine is aturbine-driven vehicle having an operator-controlled member at thedriving station, comprising means responsive .to the rotational speed ofthe shaft of the turbine and displaceable when said shaft exceeds apredetermined speed, an electrical switch having a member movable toopen and close said switch, a floating lever having a fulcrum and twoarms, means connecting the fulcrum of said lever to said movable memberof the switch, means connecting one arm of said lever to said speedresponsive means and means connecting the other of said arms to saidoperator-controlled member, movement of said movable member to operatesaid switch being thus effected by the resultant movement of saidspeedresponsive means and said operator-controlled member.

2. A device for indicating excessive speed of the turbine of aturbine-driven vehicle having an operatorcontrolled throttle, meansresponsive to the rotational speed of the shaft of the turbine andcomprising a member displaceable when said shaft exceeds a predeterminedspeed, an electrical switch having a member movable to open and closesaid switch, signal means controlled by said switch, a floating leverhaving a fulcrum and two arms, means connecting the fulcrum of saidlever to said movable member of the switch, means connecting one arm ofsaid lever to said displaceable member of said speed responsive means,means connecting the other of said arms to said throttle, movement ofsaid movable member to operate said switch being thus effected by theresultant action of said speed-responsive means and said throttle.

3. A device according to claim 2, in which the connection between thefulcrum of said lever and said movable member of the switch includes anactuating member connected to said fulcrum, a switch-operating membermovable by said actuating member in a direction to close said switch butnot in the opposite direction, means for bolding said switch in closedposition and operator-controlled means for releasing said holding means.

References Cited in the file of this patent UNITED STATES PATENTS563,544 Bateman Judy 7, 1896 1,491,712 Low Apr. 22, 1924 1,663,098 RueggMar. 20, 1928 2,019,410 Hallman Oct. 29, 1935 2,278,939 Muehter Apr. 7,1942 2,297,233 Meer Sept. 29, 1942 2,380,491 Ball July 31, 1945

